Simulating a Chern Insulator with𝐶C=±2 on Synthetic Floquet Lattice

The synthetic Floquet lattice,generated by multiple strong drives with mutually incommensurate frequencies,provides a powerful platform for quantum simulation of topological phenomena.In this study,we propose a 4-band tight-binding model of the Chern insulator with a Chern number𝐶=±2 by coupling two layers of the half Bernevig–Hughes–Zhang lattice and subsequently mapping it onto the Floquet lattice to simulate its topological properties.To determine the Chern number of our Floquet-version model,we extend the energy pumping method proposed by Martin et al.[2017 Phys.Rev.X 7041008]and the topological oscillation method introduced by Boyers et al.[2020 Phys.Rev.Lett.125160505],followed by numerical simulations for both methodologies.The simulation results demonstrate the successful extraction of the Chern number using either of these methods,providing an excellent prediction of the phase diagram that closely aligns with the theoretical one derived from the original bilayer half Bernevig–Hughes–Zhang model.Finally,we briefly discuss a potential experimental implementation for our model.Our work demonstrates significant potential for simulating complex topological matter using quantum computing platforms,thereby paving the way for constructing a more universal simulator for non-interacting topological quantum states and advancing our understanding of these intriguing phenomena.

Wave-particle duality relation with a quantum N-path beamsplitter

The wave-particle duality relation derived by Englert sets an upper bound of the extractable information from wave and particle properties in a two-path interferometer.Surprisingly,previous studies demonstrated that the introduction of a quantum beamsplitter in the interferometer could break the limitation of this upper bound,due to interference between wave and particle states.Along the other line,a lot of efforts have been made to generalize this relation from the two-path setup to the N-path case.Thus,it is an interesting question that whether a quantum N-path beamsplitter can break the limitation as well.This paper systemically studies the model of a quantum N-path beamsplitter,and finds that the generalized wave-particle duality relation between interference visibility and path distinguishability is also broken in certain situations.We further study the maximal extractable information's reliance on the interference between wave and particle properties,and derive a quantitative description.We then propose an experimental methodology to verify the break of the limitation.Our work reflects the effect of quantum superposition on wave-particle duality,and exhibits a new aspect of the relation between visibility and path distinguishability in N-path interference.Moreover,it implies the observer's influence on wave-particle duality.

Anomalous negative magnetoresistance in quantum dot Josephson junctions with Kondo correlations

The interplay between superconductivity and the Kondo effect has stimulated significant interest in condensed matter physics.They compete when their critical temperatures are close and can give rise to a quantum phase transition that can mimic Majorana zero modes.Here,we have fabricated and measured Al-InSb nanowire quantum dot-Al devices.In the Kondo regime,a supercurrent-induced zero-bias conductance peak emerges.This zero-bias peak shows an anomalous negative magnetoresistance(NMR)at weak magnetic fields.We attribute this anomalous NMR to quasiparticle trapping at vortices in the superconductor leads as a weak magnetic field is applied.The trapping effect lowers the quasiparticle-caused dissipation and thus enhances the Josephson current.This work connects the vortex physics and the supercurrent tunneling in Kondo regimes and can help further understand the physics of Josephson quantum dot system.